I was recently given a 45g tall tank from a friend that was getting out of the hobby (free, yes!) and I really like the prospect of having discus'. But I'm slightly confused.

Can I keep discus in a tank this size, and if so, how many? As with all things on the Internet, I've come across some (a lot of) conflicting information, and I want to make sure I do right by the fish.

As someone who has kept Oscars for years, and also has a SW tank, I understand the importance of appropriate tank size for species.